<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script src="js/jquery.min.js"></script>
    <title>Title</title>
</head>
<body style="width:100%; height:100%;">

<table id="mytable" border="1" width="37%">
    <thead></thead>
    <tr>
        <td width="63" >11</td>
        <td width="68" >12</td>
        <td width="62" >13</td>
        <td width="75" >14</td>
    </tr>
    <tr>
        <td width="63" >21</td>
        <td width="68" >22</td>
        <td width="62" >23</td>
        <td width="75" >24</td>
    </tr>
    <tr>
        <td width="63" >1</td>
        <td width="68" >1</td>
        <td width="62" >1</td>
        <td width="75" >1</td>
    </tr>
</table>

<script type="text/javascript">
    function countRowTotal1() {

        $('#mytable tr').each(function() {
            var rowTotal = 0;
            $(this).find('td').each(function() {
                rowTotal += parseFloat($(this).text());
            });
//	alert(rowTotal);
            //将一行的结果，写入合计列，这里直接追加到列尾
            $(this).append('<td>'+rowTotal+'</td>');
        });
    }
    countRowTotal1();
</script>
</body>
</html>
</body>
</html>